Perhaps some of the following tips taken from the Hoarding Disorder article by OCD UK might be of help.
I know they're not specifically audio related but OCD does seem to be a particularly adaptive form of affliction.
I should know, and even though I love having more living space,
I've still barely kept mine in check, although I'm fairly sure my wife would disagree. Thankfully, she is not a hoarder.
Anyway, here are few of the tips and things not to do mentioned in that article:
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Throw things away straightaway without checking.
Throw things away at times the refuse collectors are coming.
Ask family and friends to join you for a decluttering day, rent a skip and direct your family/friends in throwing clutter for you.
Get a paper shredder.
If you can’t remember the reason why you have it, get rid of it.
Buy things in limited quantities, and do not restock until used. Stop junk mail, newspapers etc.
There are some things family members should not do:
Do not get extra storage space. This won’t solve the problem and the clutter often quickly builds up again.
Do not call in the council or environmental health to clear the rubbish away without the persons permission, otherwise this could cause additional psychological distress.
Do not push the subject if the person is getting upset and angry when bringing it up. Take a step back, and try again another time.